Vertical Vent Tables And Figures - Lennox MPDT33RNM Installation Instructions Manual

LENNOX HEARTH PRODUCTS • MERIT PLUS
VERTICAL VENT FIGURES/TABLES
NOTE: Secure Vent (rigid vent pipe) is shown
®
in the figures; Secure Flex
may also be used.
NOTE: It is very important that the horizontal/
inclined run be maintained in a straight (no
dips), slightly elevated plane. The recommended
incline is approximately 1/4" per foot (20 mm
per meter) horizontal, in a direction away from
the fireplace. The rise per foot run ratios that
are smaller are acceptable all the way down to
at or near level.
NOTE: SV4.5VF (Secure Vent), SF4.5VF (Secure
Flex ) firestop/spacer must be used anytime
®
vent pipe passes through a combustible floor
or ceiling. SV4.5HF (Secure Vent), SF4.5HF
(Secure Flex )firestop/spacer must be used
®
anytime vent pipe passes through a combustible
wall.
NOTE: Two 45 degree elbows may be used in
place of one 90 degree elbow. The same rise
to run ratios, as shown in the venting figures
for 90 elbows, must be followed if 45 degree
elbows are used.
NOTE: An elbow is acceptable as 1 foot of
vertical rise, except where an elbow is the
only vertical component in the system. (See
Figure 36 on Page 21).
Max. 40 ft
Ceiling
(12.2 m)
Firestop/
Spacer
SV4.5VF*
A Vent Restrictor, as shown in Figure 17 on
Page 13, must be used in this application.
Figure 27 - Top Vent - STRAIGHT
16
®
H Maximum
(flexible vent pipe)
®
feet
2
4
6
8
V + H = 40 feet (12.2 meters) Max.
This table shows a 1 (V) to 2 (H) ratio.
For every 1 foot of (V) vertical, you are
allowed 2 feet of (H) horizontal run, up
to a maximum horizontal run of 8 feet.
Example: If 8 feet of (H) horizontal vent
run is needed, then 4 feet minimum (V)
vertical vent will be required.
Figure 28 - Rear Vent - ONE 90-DEGREE ELBOW
V1
*When using Secure Flex, use
Ceiling Firestop/Spacer SF4.5VF.
**When using Secure Flex, use
Wall Firestop/Spacer SF4.5HF.
*When using
Secure Flex, use
Ceiling Firestop/
Spacer SF4.5VF.
Figure 29 - Top Vent - TWO 90-DEGREE ELBOWS
Under no circumstances, may separate sections of concentric flexible vent
pipe be joined together.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
DIRECT VENT GAS FIREPLACES (MPD33/35/40/45) • INSTALLATION INSTRUCTIONS
TABLE A
V Minimum
(meters) (meters)
feet
(0.610) 1 (0.305)
(1.219) 2 (0.610)
(1.829) 3 (0.914)
(2.438) 4 (1.219)
H = 8 feet (2.4 meters) Max.
Ratio V to H ratio is 1:2
H
Ceiling
Firestop/Spacer
SV4.5VF*
Wall
Firestop/Spacer
SV4.5HF**
Ceiling
Firestop/Spacer
SV4.5VF*
*When using Secure Flex, use
Ceiling Firestop/Spacer SF4.5VF.
V
H
NOTE: Install the U-shaped vent restrictor in
any vent run with more than 8 ft of vertical rise
(See Page 13).
TABLE B
H Maximum
(meters)
feet
5 (1.524)
(1.524)
5
(3.048)
10
(4.572)
15
(6.096)
20
V + V + H = 40 feet (12.2 m) Max.
1
H = 20 feet (6.096 meters) Max.
Example: If 20 feet of (H) horizontal vent
run is needed, then 4 feet minimum of
(V) vertical vent will be required.
This table shows a 1 (V) to 5 (H) ratio.
V
For every 1 foot of (V) vertical, you are
allowed 5 feet of (H) horizontal run, up
to a maximum horizontal run of 20 feet.
An elbow is acceptable as 1 foot of vertical
rise except where an elbow is the only
vertical component in the system. See
Figure 36.
NOTE: Install the U-shaped vent
restrictor in any vent run with more
than 8 ft of vertical rise (See Page 13).
WARNING
V Minimum
(meters)
feet
Elbow Only
(0.305)
1
(0.610)
2
(0.914)
3
(1.219)
4